Pesticide alternatives too long in pipeline

The demand for alternative approaches to crop protection methods is rising and progress is being made by researchers, but this is not happening fast enough.

This is according to one researcher in the first edition of Crops Extra, produced in association with BASF.

The future of crop protection is going to be challenging, says Toby Bruce of Rothamsted Research, who believes that the development of alternative approaches will have to take place at a much faster rate than is currently happening.

This urgency for innovation has been created by the loss of existing active ingredients, together with the need to maintain crop yields and quality, he points out, especially given the limited amount of new chemistry in the pipeline.

“There are some developments in the agrochemical world, but they’re few and far between,” he reports. “A good example is the diamides, which are insecticides based on a new mode of action and work by targeting the calcium channel of insects.

“At this stage, they look as though they will be effective on aphids, as well as caterpillar pests. And they are based on new chemistry.”

But new chemistry comes at a higher price, acknowledges Prof Bruce, who believes that it is still required for broad-acre crops.

Biological control agents are great in a contained environment, such as a glasshouse, but in the field the concept is trickier to get right. The predators tend to fly away or get predated themselves.”

While his work has largely been focused on crop pests, he highlights that weed and disease control is also causing facing many of the same challenges. “There are resistance issues, economic constraints and environmental pressures with the current chemical armoury. Some crops are very vulnerable to attack.”

Looking ahead to future developments, he highlights the potential role of plant defence activators. “There has been work done with a compound called cis-jasmone, for example, which induces the plant’s own defence mechanism when it is applied to the crop.”

The compound is extracted from the oil of the jasmine flower and can be sprayed on to crops using existing equipment, he explains. “It doesn’t have the same efficacy as an agrochemical but it has shown a consistent, significant reduction in aphid populations.”

Prof Bruce suggests that conservation biological control – where the crop is made attractive to natural predators – will have a place. “On a practical level, it means providing nectar sources for the predators to feed on and avoiding blanket spraying.”

Another technique which is being evaluated in other parts of the world is companion cropping, so that root exudates from the companion species can be used to help suppress weeds, reveals Prof Bruce.


To read the full article, see the 19 October edition of Crops Extra.


Crops Extra

This month sees the first special edition of Crops magazine, in association with BASF, in addition to the regular editions of the magazine. The first Crops Extra edition focuses on crop protection, looking at legislation and how this will affect growers, future developments and an examination into research projects looking at possible alternatives. To ensure you get your own copy of Crops, ring our subscription hotline (08444 4122 294) or visit www.fwi.co.uk/cropsregister


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